1. Field of the Invention.
This invention relates to needle actuating camming for knitting machines, and especially to needle actuating camming for high speed circular knitting machines.
2. Description of the Prior Art
It has been the practice to provide separate raise and stitch cams in circular knitting machines for raising and lowering knitting needles and to permit needles to move between the raise and stitch cams without being positively controlled. Large impact forces resulted whenever a needle butt first engaged a raise cam after leaving a stitch cam, or first engaged a stitch cam after leaving a raise cam, and the cam surface as well as the needle butts sustained excessive wear and damage as a consequence. Such impact forces increase with increased speeds and it therefore became necessary to run machines at quite limited speeds in order to prevent frequent shut-downs for repair. Also in the extent to which there was a lack of positive control of needles by a closed cam track closely confining needle butts as they were actuated by raise and stitch cams, needle butts tended to bounce off the surfaces of raise and stitch cams and of guard cams causing excessive vibration, noisy operation of the machine and excessive wear and damage to the engaging parts.